تعيين برخي خصوصيات بيولوژيكي و مولكولي Potato leafroll virus و Potato virus A در استان اصفهان

چكيده انگليسي :

87 Determination of certain biological and molecular characteristics of Potato leafroll virus and Potato virus A in Isfahan province Rozita Seifi Seifi rozi@yahoo com Date of submission Department of Plant Protection Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language Farsi 1 A Massah Ph D Assist Professor Supervisor amassah@cc iut ac ir 2 M Bahar Ph D Assoc Professor Supervisor mbahar@cc iut ac ir Abstract Potato is one of the most important crops in the world Several viruses affect potato crop and cause significant economic losses Potato leafroll virus PLRV is a member of genus Polerovirus and family Luteoviridae and Potato virus A is a member of genus Potyvirus and family Potyviridae are the most common viruses of potato These viruses were transmitted in persistent and non persistent manner by aphids respectively Since in recent years the PLRV and PVA are known as serious threats in potato fields of Iran and lack of enough information about molecular characteristics of them this research was conducted to detect and determine the molecular characteristics of these viruses in Isfahan and Charmahal va Bakhtiari provinces For this purpose potato samples with symptoms of PLRV and PVA were collected in 2011 and 2012 Infection of samples with PVA symptoms including mild mosaic and leaf stunting were tested by double antibody sandwich enzyme linked immunosorbent assay DAS ELISA In DAS ELISA 5 out of 32 leaf samples and 3 out of 35 tuber samples were tested positive Total RNA was extracted from PVA positive samples and other samples showing PVA symptoms and were subjected to RT PCR using PVA specific primer pairs PVAf PVAr and Primer3 F Primer4 R The expected PCR products 255 bp and 1100 bp were amplified in two samples The amplicons were cloned and sequenced No homology found in BLAST comparison between sequenced samples and PVA isolates available at GenBank Because of presence of serological relationships between potyvirus species it seems a virus different from PVA or at least a virus related to PVA was detected in DAS ELISA The extracted total RNA of samples showing PLRV symptoms including yellowing and leaf rolling was used in RT PCR with PLRV0 F PLRV0 R primer pair amplifying full length of PLRV ORF0 Some samples amplified expected size of 820bp Amplified fragments of seven isolates representing different regions were selected and sequenced for molecular comparisons The BLAST search revealed high similarity between ORF0 nucleotide sequence of the Iranian isolates and those of other PLRV isolates available at GenBank Multiple alignment of the ORF0 amino acid sequence of PLRV Iranian isolates and those of PLRV isolates available at GenBank revealed high homology ranging from 90 to 100 among them All Iranian isolates except Fereidan and Ben isolates showed highest Homology 99 1 100 with the Czech Republic EU717546 and Egyptian AY138970 isolates and lowest Homology 96 1 96 9 with Iranian isolate JF914941 respectively The Fereidan isolate showed highest Homology 98 7 with the Germany JQ346189 isolate and ben isolate showed highest Homology 100 with Spanish AF453389 isolates Fereidan isolate showed lowest similarity 91 7 with Cuba AF453393 isolate Phylogenetic analysis revealed almost all Iranian isolates grouped in one cluster and no clear assortment by geographical regions Key word Potato leafroll virus Potato virus A RT PCR Alignment Phylogenetic tree

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تعيين برخي خصوصيات بيولوژيكي و مولكولي Potato leafroll virus و Potato virus A در استان اصفهان

ويروس پيچيدگي برگ سيب زميني , ويروس اي سيب زميني , همرديف سازي , درخت تبارزايي